Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Bpk 205 > Lec 16/17 > Flashcards

Lec 16/17 Flashcards

1
Q

Function of each lobe

A

Frontal: skeletal muscle movements
Parietal: somatic sensory cortex
Occipital: vision
Temporal: hearing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Primary motor cortex contain

A

Cell body of upper motor neurons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Upper motor neurons are part of

A

CNS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Axons of upper motor neurons will synapse in

A

Grey matter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Lower motor neurons are

A

PNS
Project to innervate skeletal muscle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Peripheral pathway consist of — lower motor neuron

A

1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Axon collateral of lower motor neuron will

A

Branch out at distal end and each collateral will synapse (neuromuscular junction) with 1 muscle fiber

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Neuromuscular junction consist

A

Axon terminal
Motor end plate on muscle membrane
Schwann cell sheaths

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Schwann cell function at NMJ

A

Secrete chemicals required for formation and maintenance of NMJ

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Motor end plate

A

Specialized region of muscle membrane that contain high concentration of nicotinic ACH receptors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Lower motor neuron will release neurotransmitters (ACH) and

A

Muscle cell has NACHR
ACH is always excitatory

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Nicotinic ACH receptor

A

Non selective cation channel

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

NACHR is non selective channel however

A

Na flow/flux is higher
In result cell will depolarize

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

ACH in NMJ is always

A

Excitatory

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Muscle cell name

A

Muscle fiber

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Cell membrane of muscle

A

Sarcolemma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Muscle cell cytoplasm

A

Sarcoplasm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Modified ER

A

Sarcoplasmic reticulum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Muscle fascicle

A

Bundle of fibers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Skeletal muscle

A

Bundle of muscle fascicle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Epimysium

A

Connective tissue around skeletal muscle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Perimysium

A

Connective tissue around muscle fascicle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Endomysium

A

Connective tissue around muscle fiber

24
Q

T-tubules

A

T-tubules are extensions of cell membrane (sarcolemma) that associate with ends of Sarcoplasmic reticulum

25
Q

Proteins within myofibril

A

Myosin
Actin
Troponin
Tropomyosin
Titin
Nebulin

26
Q

Sarcomere

A

Unit of myofibril between 2 z-disks

27
Q

Skeletal muscles contain

A

Organized sarcomeres
Striped or striated
Like cardiac muscle

28
Q

Striation of skeletal muscle is

A

Alternation between A band and I band

29
Q

Myosin

A

Thick filament
Motor unit create movement
2 intertwined protein chains
Each myosin one actin binding site/one ATP binding site(ATP hydrolyses)

30
Q

Thick filament= —— myosin molecules

A

250

31
Q

Actin molecule

A

One actin=Globular g-actin
Polymerize to form F-actin
Each G-actin single myosin binding site

32
Q

Thin filaments

A

Two chains of F-actin intertwined

33
Q

Troponin

A

Trimeric protein
Bind to tropomyosin has 2 cCa binding site

34
Q

Tropomyosin

A

Long protein dimer attach to actin
Covering the myosin binding site
— so myosin cannot securely attach

35
Q

Titin

A

Huge, elastic, resting length
One Z disk to neighboring M line
Return stretched muscle to resting length

36
Q

Nebulin

A

Along thin filaments
Attach z disk but does not reach M line — inelastic molecule
Structural support for thin filament

37
Q

Molecules required for cross-bridge

A

Ca ion—enable myosin heads to attach actin by revealing myosin binding site
high-force cross-bridge formation
ATP—bind to myosin and allow it to detach from actin
cross-bridge cycling

38
Q

Without Ca

A

-Troponin is inactive
-Tropomyosin partially block myosin
-Myosin can bind to actin only weakly
-Low-force cross-bridge

39
Q

By increase in [Ca]

A

-activate troponin
-pulls tropomyosin away from myosin binding site
-myosin bind strongly to actin/complete power stroke
-actin filament moves

40
Q

Contraction cycle

A

1- ATP bind to myosin/myosin release actin
2- Myosin hydrolyze ATP
3- Energy from ATP will rotate myosin head
4- Power stroke happen (tropomyosin moves away)
5- myosin release ADP at the end of power stroke

41
Q

What doesn’t change length

A

Thick and thin filament
A band

42
Q

What change length during contraction

A

I band
H zone
Sarcomere shorten (z line closer)

43
Q

Excitation-Contraction coupling in skeletal muscle

A

1- somatic motor neurons release ACh at NMJ
2- net entry of Na from ACH-receptor-channels
3- AP
4- ap move in t-tubule
5- alter conformation DHP receptor
6- DHP open RyR channels in Sarcoplasmic reticulum which are mechanically gated
7- Ca enter cytoplasm
8- Ca bind to troponin
9- allow actin-myosin binding
10- myosin head execute power stroke
11- actin filament move toward centre of sarcomere

44
Q

Skeletal muscle relaxation (Ca removal)

A

1- sarcoplasmic Ca-ATPase (SERCA) pumps Ca back into SR
2- decrease free cytosolic Ca
3- Ca unbind with troponin
4- tropomyosin recovers binding site
5- myosin head release
6- titin pull filaments back to their relaxed position

45
Q

Muscle twitch

A

One contraction + one relaxation
In a single fiber

46
Q

Forces in skeletal muscle can

A

Sum

47
Q

Summation can lead to

A

1- unfused tetanus
2- complete tetanus

48
Q

Unfused tetanus

A

Allow muscle to relax slightly between stimuli

49
Q

Complete tetanus

A

Steady tension
No break
Full capacity

50
Q

Motor unit

A

One motor neuron and the muscle fiber it innervate

51
Q

Size of motor neuron related to

A

Need of refined movement

52
Q

More refined movement’

A

Fewer fibers per motor unit

53
Q

Order the motor units recruited is related to

A

Power needed to generate movement
— smaller motor unit recruited first

54
Q

Smaller motor neuron

A

Lower threshold for activation
Activate by lower frequency of stimulation from CNS

55
Q

Sarcomers contract with maximum force when ———

A

They are in their normal resting length prior to contraction
— optimal number of cross-bridges

Bpk 205 (30 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions